It is extremely important that power semiconductor devices keep high insulation properties while efficiently dissipating heat generated by power chips to the outside. An insulating layer located below the power chips is preferably thin to increase heat dissipation characteristics, but it is feared that the thin insulating layer reduces the insulation properties.
Moreover, the power semiconductor devices often adopt semiconductor devices having a resin-sealed structure entirely full-molded with one type of resin. For example, Patent Document 1 discloses a semiconductor module as a semiconductor device having a resin-sealed structure.